From BiblePortal Wikipedia

Hastings' Dictionary of the Bible [1]

Giloh . A city in the southern hills of Judah (  Joshua 15:61 ), the birthplace of Ahithophel the Gilonite , the famous counsellor of David (  2 Samuel 15:12;   2 Samuel 23:34 ). Its site is uncertain.

American Tract Society Bible Dictionary [2]

A city of Judah,  Joshua 15:50; where Ahithophel, David's counselor dwelt; and where, after his treason against David, and the rejection of his counsel by Absalom, he hung himself,  2 Samuel 15:12;  17:23 .

Morrish Bible Dictionary [3]

Town in the highlands of Judah, the native place of Ahithophel.  Joshua 15:51;  2 Samuel 15:12 . Identified with ruins at Jala , 31 37' N, 35 4' E .

Fausset's Bible Dictionary [4]

A town in the hills of Judah ( Joshua 15:51); the native place of Ahithophel ( 2 Samuel 15:12;  2 Samuel 17:23).

Easton's Bible Dictionary [5]

 Joshua 15:51 Joshua 15:51 2 Samuel 15:12

Holman Bible Dictionary [6]

 Joshua 15:51 2 Samuel 15:12

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [7]

(Heb. Giloh', גַּלֹה , Exile [Gesenius] or circle [Furst]; Sept. in Joshua Γιλώ v. r. Γηλώμ and Γηλών , in Sam. Γελώ v.r. Γωλά ), the last named (after Goshen and Holon) in the first group of eleven cities in the south-western part (Keil, Joshua page 384) of the hill-country of the tribe of Judah ( Joshua 15:51); and afterwards the native place or residence of Ahithophel (hence called "the Gilonite" [q.v.],  2 Samuel 15:12;  2 Samuel 23:34), whence Absalom, on his way from Jerusalem to Hebron, summoned him (perhaps from a temporary banishment or disgrace at court) to join his rebellious standard ( 2 Samuel 15:12), and whither he returned to commit suicide on the failure of his colleagues to adopt his crafty counsel ( 2 Samuel 17:23). Josephus calls it Gelmon ( Γελμών , Ant. 7:9, 8). De Saulcy (Dead Sea, 1:453) and Schwarz (Palest. page 105) both make it to be the modern Beit-Jala, near Bethlehem; but this is rather the ancient Zelah or Zelzah (q.v.), and the scriptural notices require a different position, perhaps at Rafat, a village with extensive ruins one hour twenty minutes south of Hebron (Van de Velde, Memoir, page 252).

International Standard Bible Encyclopedia [8]

gı̄´lō ( גּלה , gilōh ): A town in the hill country of Judah mentioned along with Jattir, Socoh, Debir, Eshtemoa, etc. (  Joshua 15:51 ). Ahithophel came from here ( 2 Samuel 15:12 ) and is called the Gilonite ( 2 Samuel 23:34 ). Driver infers from this last that the original form was Gilon, not Giloh. Probably the ruins Kḣ Jālā , in the hills 3 miles Northwest of Hulhūl , mark the site ( PEF , III, 313, Sh Xxi ).